Human immunodeficiency virus (HIV) is a lentivirus that cause acquired immunodeficiency syndrome (AIDS), in which progressive failure of the immune systems can allow life-threatening infections to thrive. Infection with HIV occurs through transfer of viral genetic material from infected individual to healthy human cells. HIV primarily infects cells in the human immune system by attaching to the CD4 sites of T-cells and injecting the viral genetic material. In view of the devastating effects of HIV and AIDS, significant research has gone into preventing transmission and new infections while simultaneously treating the infected individuals.
Many pharmacologic compositions have been proposed for reducing HIV transmission and infection as well as for the treatment of HIV. For example, the drug Tenofovir has been widely studied for treatment and pre-exposure prophylaxis/post-exposure prophylaxis of HIV. Travuda (Tenofovir/Emtricitabine) is currently the only FDA approved drug for pre-exposure prophylaxis in high risk uninfected individuals. Standard treatment regimen for post-exposure prophylaxis involves a combination of 2 NRTIs (Nucleoside Reverse Transcriptase inhibitors)+1 PI (Protease inhibitor) or 2 NRTIs+1 NNRTI (Non-Nucleoside Reverse Transcriptase Inhibitor). The effectiveness of current pharmacologic interventions has proven limited and was not proven to completely prevent. HIV transmission.
It is believed that sexual transmission accounts for approximately 90% of HIV infection. Though promising, none of the mucosal microbiocides and/or oral therapies have demonstrated effective protection against the sexual transmission of HIV. In fact, attempts to develop an effective vaginal gel to reduce HIV transmission and infection have not proven fruitful. For example, attempts to incorporate Tenofovir, an NRTI, into a vaginal gel have not proven sufficiently effective for reducing the transmission and/or infection of HIV via sexual transmission.
Tenofovir is an antiretroviral drug belonging to the class of nucleotide analogue reverse transcriptase inhibitors (NRTI), which can block reverse transcriptase, an enzyme crucial for the production of viral genetic material in HIV infected people. Tenofovir is currently employed as a first line treatment option for HIV patients because of good therapeutic potency, low overall toxicity, and dosing convenience. This drug is administered orally in the form of disoproxil ester prodrug, which is deesterified to release the active drug (tenofovir) with a bioavailability of ≥20%. It should be understood that other drugs may also be useful for pre-exposure prophylaxis, post-exposure prophylaxis and/or treatment of HIV.